Thought I'd post this since I couldn't find an intact chart with this information elsewhere.
As many of you already know, XP gain isn't linear (see "Experience is a River"). Just flip your DMG open to page 38, and you’ll see a chart that indicates how XP gain works. Each time you complete an encounter, you gain an amount of XP based on the challenge rating of the encounter
and your level. If a character of a lower level completes the same challenge, they gain more XP than a higher level character completing the same challenge.
The upshot of this is that XP costs don’t keep you behind the curve permanently. You can use a ton of abilities with XP costs and never get more than one encounter behind the other PCs, so long as you don’t just spam these abilities (in fact, it’s technically possible to slightly overshoot the XP of other PCs due to getting “overflow XP” from the last encounter of a level). In other words, you shouldn’t be afraid to craft items or prepare things like Alter Fortune, and if you lose a level for dying you aren’t just permanently screwed.
You can afford to use a few abilities with XP costs and never get more than one encounter behind the other PCs, so long as you don’t just spam these abilities (in fact, it’s technically possible to slightly overshoot the XP of other PCs due to getting “overflow XP” from the last encounter of a level). In other words, you shouldn’t be afraid to craft items or prepare things like Alter Fortune, and if you lose a level for dying you aren’t just permanently screwed.
Alternatively, you could treat “spams XP cost abilities” as a sort of LA+1 template that you can’t buy off, and use the constant bonus XP from being a level behind to fuel your abilities with XP costs. This can lead to item crafting characters that have much more wealth than usual, which may be worth staying a level behind for some.
But let's skip to the chase.
Level Adjustment and the River:LA tends to be fairly crippling in D&D. Put simply, odds are that if you have an LA+2 race, the LA+2 race’s benefits likely aren’t worth as much as 2 class levels. This becomes especially true at higher levels, where it’s unlikely that your LA+2 race’s benefits are worth even one class level. A common solution is to use the LA buyoff variant in Unearthed Arcana, found here:
http://www.d20srd.org/srd/variant/races/reducingLevelAdjustments.htmThe benefit of the LA buyoff variant is that you can spend a flat XP cost to “buy off” your LA at certain levels, at which point you’ll start to catch up to your teammates due to the effect of being a level behind. If you’re playing a game from 1-20, this is pretty straightforward. However, if you’re starting at, say, level 10, then applying the effect of the XP river and LA buyoff calculations retroactively can be rather non-trivial. So, to save you time, I’ve done the math for you! Simply look up what level a “normal” character is starting at, and the following charts will give you your level and XP if you have LA+1 or +2.
LA BUYOFF (LA+1, no racial hit dice)Calculations done assuming you receive 13⅓ encounters of each CR level, divided amongst 4 players (e.g. standard assumptions according to the DMG).
If everyone else just hit level X, you are Y (With Z XP)
to Level 1: You don’t exist
to Level 2: Level 1 (1,000XP)
to Level 3: Level 2 (3,000XP)
to Level 4: Level 3 (3,000XP) (You just bought off your LA! Now the XP River starts to kick in)
to Level 5: Level 4 (7,337.5 XP)
to Level 6: Level 5 (12,512.5 XP)
to Level 7: Level 6 (19,075 XP)
to Level 8: Level 7 (26,525 XP)
to Level 9: Level 8 (34,900XP)
to Level 10: Level 9 (44,350 XP)
to Level 11: Level 10 (54,612.5 XP)
to Level 12: Level 11 (65,912.5 XP)
to Level 13: Level 13 (78,250 XP)
So, there you have it. Using the above methodology, LA+1 becomes free by level 13 with LA buyoff. Differences in the order in which encounters are received can affect your overflow rate and thus change what level you “catch up” at but this should calibrate your expectations. Note also that even though you won't be permanently caught up until around level 13, you'll spend a while only lagging a couple of encounters behind them.
Examples of worthwhile (yet not wildly broken) LA+1s: Chaos Gnome, Goliath, Draconic
If your DM allows LA Buyoff, you can expect your Powerful Build to become free by level 13LA BUYOFF (LA+2, no racial hit dice)to Level 1: You don’t exist
to Level 2: You don’t exist. I’d say it sucks to be you, but nothing can be you, because you can’t be something that doesn’t exist.
to Level 3: Level 1 (3000XP)
to Level 4: Level 2 (6000XP)
to Level 5: Level 3 (10000XP)
to Level 6: Level 4 (15000XP)
to Level 7: Level 5 (21000XP)
to Level 8: Level 6 (21000 XP) (You just bought off part of your LA and are now ECL 7. The XP river starts to kick in)
to Level 9: Level 7 (30687.5XP)
to Level 10: Level 8 (41037.5XP)
to Level 11: Level 10 (45,450XP)
(You just bought off your LA again mid-way through here, and are now ECL 10. You actually manage to ding twice here, but you’re still a level behind your companions)
Note: By the time everyone else is level 11, you are 1 level behind instead of 2.
to Level 12: Level 11 (58,750XP)
to Level 13: Level 12 (72,775XP)
to Level 14: Level 13 (87,650XP)
to Level 15: Level 14 (102,887.5XP)
to Level 16: Level 15 (118,787.5XP)
to Level 17: Level 16 (135,275XP)
to Level 18: Level 17 (152,800XP)
to Level 19: Level 19 (171,362.5 XP)
LA +2 becomes “free” by level 19. You are only one level behind your companions by level 11.
Notes: If the XP rate is faster, or you’re typically facing encounters of higher CR than your own, or there are less PCs in the party, then you’ll tend to get more overflow due to XP coming in larger individual chunks, and you will catch up faster. If the XP rate is slower, or you’re typically facing encounters of lower CR than your own, or there are more PCs in the party, you’ll tend to get less overflow due to XP coming in smaller individual chunks, and you will catch up slower.
A Note on Ad Hoc XP: Many groups don’t like to give out XP by encounter, and indeed the DMG itself offers a few variants for handing out XP. However, sometimes these groups forget to take the “XP river” into account, and this is rather punitive to characters who fall behind on XP for any reason. XP costs suddenly become much more onerous, and a character who loses a level from death simply stays behind
forever. For those who want to maintain the ability of players to “catch up” while not worrying about the encounter XP system, a question arises as to how much they should be scaling their XP rewards for lower level characters.
One answer is rather simple. Simply treat your roleplaying / quest / whatever XP as encounters with a given CR, and reference the encounter table. If you want smaller or larger chunks of XP, just multiply or divide. You may want to be careful about handing out larger chunks of XP, however, since this can result in players who are behind getting more overflow XP than usual. If you are going to hand out XP for entire adventures, you could instead hand it out as if it were “X encounters.”
Cheers,
Ludic
